// SPDX-License-Identifier: GPL-2.0

#include "vmlinux.h"

#include <bpf/bpf_helpers.h>
#include <bpf/bpf_tracing.h>

char _license[] SEC("license") = "GPL";

int ca_cnt = 0;
bool cong_control = false;

static inline struct tcp_sock *tcp_sk(const struct sock *sk)
{
    return (struct tcp_sock *)sk;
}

SEC("struct_ops/ca_update_init")
void BPF_PROG(ca_update_init, struct sock *sk)
{
    ca_cnt++;
}

SEC("struct_ops/ca_update_2_init")
void BPF_PROG(ca_update_2_init, struct sock *sk)
{
}

SEC("struct_ops/ca_update_cong_control")
void BPF_PROG(ca_update_cong_control, struct sock *sk,
          const struct rate_sample *rs)
{
}

SEC("struct_ops/ca_update_cong_control2")
void BPF_PROG(ca_update_cong_control2, struct sock *sk,
          const struct rate_sample *rs)
{
    cong_control = true;
}

SEC("struct_ops/ca_update_ssthresh")
__u32 BPF_PROG(ca_update_ssthresh, struct sock *sk)
{
    return tcp_sk(sk)->snd_ssthresh;
}

SEC("struct_ops/ca_update_undo_cwnd")
__u32 BPF_PROG(ca_update_undo_cwnd, struct sock *sk)
{
    return tcp_sk(sk)->snd_cwnd;
}

SEC(".struct_ops.link")
struct tcp_congestion_ops ca_update = {
    .init = (void *)ca_update_init,
    .cong_control = (void *)ca_update_cong_control,
    .ssthresh = (void *)ca_update_ssthresh,
    .undo_cwnd = (void *)ca_update_undo_cwnd,
    .name = "tcp_ca_update",
};

SEC(".struct_ops")
struct tcp_congestion_ops ca_update_2 = {
    .init = (void *)ca_update_2_init,
    .cong_control = (void *)ca_update_cong_control2,
    .ssthresh = (void *)ca_update_ssthresh,
    .undo_cwnd = (void *)ca_update_undo_cwnd,
    .name = "tcp_ca_update_2",
};

SEC(".struct_ops.link")
struct tcp_congestion_ops ca_wrong = {
    .cong_control = (void *)ca_update_cong_control,
};
